Meteorite's Black Glass May Reveal Secrets of Mars

Below:

Next story in Space

Black glass from a Martian meteorite that crashed in Morocco last
summer may shed light on not only the surface of the Red Planet
but also its interior and atmosphere, a new study reveals.

Rocks are occasionally blasted off the surface of Mars by cosmic
impacts from asteroids. These drift in space, with some crashing
down on Earth. Martian rock known to be on Earth is very rare:
only about 220 pounds (100 kilograms) worth.

Last July, a swarm of Martian meteorites plunged into the
Moroccan desert. These rocks, named
Tissint meteorites after the village they landed near, were
the first batch of Martian meteorites to be collected right after
observers witnessed their fall. All the other Martian meteorites,
many of them recovered from Antarctica, had been gathered well
after arrival, during which time degradation and contamination
may have obscured secrets they held about Mars.

Within a Tissint meteorite, scientists found an abundance of
black glass that they say may contain traces of Mars' surface,
atmosphere and interior. This glass preserved key details about
Mars. [ Black
Glass in New Martian Meteorite (Photos) ]

The black glass resulted from melting, probably caused by the
impact that knocked the rock off Mars an estimated 700,000 years
ago.

The meteorite is mostly a kind of volcanic rock known as basalt,
rich with an olive-green crystal known as olivine. This suggests
it once was part of Mars' interior. However, levels of sulfur,
fluorine and trace elements such as cesium hint at material from
the Martian surface. In addition, the glass contains bubbles of
Martian atmosphere.

To explain the presence of the interior, surface and atmosphere
of Mars in one meteorite, the researchers suggest the rock's
cracks and fissures were infiltrated by fluids washing down from
the Red Planet's surface.

"It was really surprising and very exciting to find the evidence
of Martian surface alteration in Tissint," lead study author
Hasnaa Chennaoui at Hassan II University in Casablanca, Morocco,
told SPACE.com. "We didn't expect this result."

The meteorite possesses certain varieties (isotopes) of helium,
neon and argon that were likely formed by collisions with the
high-energy-charged particles of cosmic rays. The isotopes reveal
the rock spent about 700,000 years in space. This makes the
Tissint rocks roughly the same age as three-quarters of all known
Martian meteorites, suggesting they all got knocked off Mars by
the same event.

The scientists detailed their findings online today (Oct. 11) in
the journal Science.

Follow SPACE.com for the latest in space science and
exploration news on Twitter@Spacedotcomand onFacebook.